Silly Putty

Silly Putty is a silicone-based toy that stretches and flows slowly but rebounds when struck. It can also lift ink from some printed pages.

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Silicone: Silicones are polymers with repeating silicon–oxygen backbones and organic side groups. Silly Putty’s silicone polymer gives the toy its distinctive stretch and rebound.
James Wright (engineer): James Wright was a General Electric engineer who created the material later marketed as Silly Putty. His experiments with silicone rubber produced the putty’s original formulation.
Toy: A toy is an object designed primarily for play, recreation, or imaginative activity. Silly Putty became a toy because its changing shapes and bouncing behavior invite experimentation.
Silly Putty egg: A Silly Putty egg is the egg-shaped retail form in which the toy was famously sold. Its packaging made the putty recognizable while inviting bouncing and reshaping.
Viscoelasticity: Viscoelasticity is the combination of elastic response and time-dependent flow in a material. Silly Putty’s response changes with how quickly it is pulled, shaped, or struck.
World War II synthetic rubber shortage: World War II created shortages of natural rubber and intensified efforts to develop substitutes. The search for substitute rubber prompted the experiments that led to Silly Putty.
Ink transfer: Ink transfer is the movement of ink from one surface to another through contact or pressure. Pressing the putty onto some printed pages can lift portions of their ink.
Silly Putty bounce test: A Silly Putty bounce test measures how the material rebounds after being dropped onto a surface. The test shows its elastic response to a sudden impact.
Polymer cross-linking: Polymer cross-linking connects polymer chains into a network through chemical or physical bonds. The network helps the putty recover after deformation instead of flowing like a simple liquid.
Silicone rubber: Silicone rubber is an elastomer made from silicone polymers, valued for flexibility and heat resistance. James Wright was trying to develop a useful rubber substitute when he made the putty.